I recommend to build your own Linux kernel packages because the kernel you are running does not match with the installed Slackware ARM packages

5. Tips and tricks

5.1. Processor

The Raspberry Pi processor can reach 1.2GHz.
However, by default, it is stuck to 600MHz even if it is used at 100%.
You can check the current frequency of the processor by typing:

$ cpufreq-info

In order to reach 1.2GHz when the processor is used at 100% (i.e., use the frequency scaling), you need to change the default governors.
Add the following line to the end of the /etc/rc.d/rc.local file:

5.2. Time

Unfortunately, the Raspberry Pi does not provide a Real-Time Clock (RTC).
That is why there is no battery included with the board.
It means that each time you shutdown the Raspberry Pi, the time is reset!
However, if you have internet access, you can update the time during the Slackware ARM boot.
Add the following line to the end of the /etc/rc.d/rc.local file:

ntpdate pool.ntp.org

Now, the time is correctly set.

5.3. Video

Unfortunately, the Raspberry Pi is not compatible with OpenGL (it is compatible OpenGL ES that is a subset of OpenGL).
It means that, by default, each application requiring OpenGL will be slow.
However, you can reach 60 FPS with OpenGL applications on the Raspberry Pi by using the correct driver.